BMI vs Waist-to-Hip Ratio: Which Is More Accurate?

What is BMI?

Body Mass Index (BMI) is one of the oldest, most widely used, and easiest methods for evaluating overall health. It takes into consideration your height and weight for calculation. The BMI formula is weight in kgs divided by height in meters squared. You can use this formula manually or use a BMI calculator to get your BMI. Map it with the BMI range to know which category you fall into. The ideal BMI is between 18.5 and 24.9.

Here is the BMI chart for your reference:

Weight Class

BMI Range

Underweight

BMI less than 18

Optimal Weight

BMI between 18.5 to 24.9

Overweight

BMI between 25 to 29.9

Class 1 Obese

BMI between 30 to 34.9

Class 2 Obese

BMI between 35 to 39.9

Class 3 Obese

BMI over 40

However, it is to be noted that the BMI results can often be misleading, especially in the lower and higher ranges. This is because the BMI does not take into account body composition and can misrepresent data for individuals with higher muscle mass, such as athletes. You can also read about BMI vs body fat percentage to understand how both relate to health assessment.

Hence, despite its popularity, BMI has its limitations and is considered a controversial screening tool, especially for overweight or obese people.

What is Waist-to-Hip Ratio?

The Waist-to-Hip ratio is a popular health screening tool that compares waist and hip measurements to measure the body’s central obesity. Now, let us see how to measure the waist-to-hip ratio. WHR is calculated by dividing your waist circumference by your hip circumference. For calculation purposes, your smallest waistline and the largest part of the hip are considered. You can also use an online waist-to-hip ratio calculator for more convenience.

Waist-to-Hip Ratio Chart

As common knowledge, a higher WHR means more fat around the waist, indicating a higher risk of chronic diseases, like heart disease or diabetes. To interpret your waist-to-hip ratio, you can map it to the World Health Organization (WHO) range for the WHR.

Here is the waist-to-hip ratio range you can refer to:

Health Risk

WHR in Women

WHR in Men

Substantially Increased Risk

0.85

0.9

The table below shows the health risk indicator in relation to the waist circumference per the WHO cut-off:

Health Risk

Waist Size in Women (in inches)

Waist Size in Men (in inches)

Increased Risk

31.5

Substantially Increased Risk

34.7

This indicates a WHR greater than 0.9 in men and 0.85 in women is considered risky. A waist circumference of 37 inches in men and 31.5 inches in women is also risky and can be a sign of an increased risk of health issues.

BMI vs Waist-to-Hip Ratio: Key Differences

Here are the key differences between BMI and waist-to-hip ratio:

Parameter

BMI (Body Mass Index)

WHR (Waist-to-Hip Ratio)

What does it measure?

It measures your weight in proportion to your height to assess if you are in a healthy range

It measures your waist in proportion to hip circumference, indicating abdominal fat

Inputs for Calculation

Height and weight

Waist and hip circumference

Formula for Calculation

Weight (kg) ÷ Height (m²)

Least circumference of waist ÷ Widest circumference of Hips

Fat Consideration

Yes

Accuracy

Appropriate for regular health screening

Higher accuracy for cardiovascular diseases

Used For

It is used to get an overall idea if the person is underweight, overweight or has the right weight

It is majorly used to calculate body fat distribution, especially around abdomen to assess central obesity risk

Limitations

Does not consider muscle mass

Requires exact measurements

BMI vs Waist-to-Hip Ratio: Which One is Better?

With both BMI and waist-to-hip ratio being widely used by health professionals, it is natural to get confused as to which one is better and more reliable.

JAMA Network Open, the monthly open-access medical journal published by the American Medical Association, compared BMI and waist-to-hip ratio. The purpose was to evaluate which one of the two is a better predictor for health risks, especially for cancer, heart issues, and even death. The study found that the WHR had the strongest and most consistent relation with health risks and mortality.

This is probably because WHR more accurately represents fat levels, especially around the waist. The fat around the waist is usually a significant indicator of visceral fat, which increases the risk of cardiovascular disease, type 2 diabetes, and fatty liver, among other conditions.

In conclusion, BMI can be used for general health screening and keeping a check on your body weight. However, the waist-to-hip ratio is a better method to assess health risks if you want a more comprehensive idea.

FAQs

Q1. Which is better, BMI or WHR?

Ans: BMI indicates the overall body weight, while the weight-to-hip ratio (WHR) measures central obesity. When considering waist-hip ratio vs BMI, WHR is considered more accurate as it provides a better representation of fat proportion. More abdominal fat indicates visceral fat around the waist, which can lead to higher risks of chronic diseases. Hence, if you want a comprehensive picture of your health, WHR is a better indicator than BMI.
Q2. Why don't doctors use BMI anymore?

Ans: BMI is one of the oldest screening tools for assessing body weight. However, the doctors now use it less extensively or do not read it alone because it considers only the weight and height of an individual. The obtained result can be misleading in many cases and may not provide a complete picture of an individual’s health risks.
Q3. What waist size indicates health risks?

Ans: According to the WHO cut-off, a waist size of 37 inches in men and 31.5 inches in women is considered risky, while a waist circumference of 40 inches in men and 34.7 inches in women is considered highly risky.
Q4. Can exercise improve my hip-waist ratio?

Ans: You can strengthen your hip muscles and reduce belly fat with adequate and regular exercise. If done consistently, it helps increase metabolism and aid in the fat loss journey. A reduced waist circumference can improve the waist-to-hip ratio.
Q5. What is the healthiest waist size for a woman?

Ans: A waist size below 31.5 inches or a waist-to-hip ratio of below 0.85 is considered healthy for a woman.
Q6. Is there a link between waist size and heart health?

Ans: Yes. Obesity around the waist often indicates visceral fat deposit, which means a higher risk of cardiovascular diseases. This implies that your heart health can be at risk if you have a larger waist size. Hence, the waist-to-hip ratio health risk should be regularly monitored to assess your heart health.
Q7. What is the healthiest hip-to-waist ratio?

Ans: The healthiest waist-to-hip ratio is less than 0.85 for women and 0.9 for men, according to WHO classifications.
Q8. How to reduce the waist-to-hip ratio?

Ans: You can reduce your waist-to-hip ratio by improving your diet, exercising and making lifestyle changes. With small changes, such as incorporating more fiber into your diet, reducing carbs and sugar, getting enough sleep, minimizing stress, adding strength training to your routine, etc., you can decrease the WHR.

BMI vs Waist-to-Hip Ratio: Which Predicts Health Risks Better?

FAQs

Q1. Which is better, BMI or WHR?

Q2. Why don't doctors use BMI anymore?

Q3. What waist size indicates health risks?

Q4. Can exercise improve my hip-waist ratio?

Q5. What is the healthiest waist size for a woman?

Q6. Is there a link between waist size and heart health?

Q7. What is the healthiest hip-to-waist ratio?

Q8. How to reduce the waist-to-hip ratio?